i need the 5-hour energy or monster to stay awake. >> reporter: the energy shots come in small bottles and can be found in your neighborhood pharmacy. the fda says it's investigating 92 patient reports, including 33 hospitalzations related to 5- hour energy, adding, if we find a relationship between consumption of the product and harm, fda will take appropriate action to reduce or eliminate the risk. >> even though it says drinking one bottle per day is okay, it's not for me. >> reporter: he says he just got out of the hospital after an adverse reaction to 5-hour energy. >> i suffered headaches and heart palpitations. i felt awful, sweating. i'm very fatigued now, actually. >> reporter: the fda warning makes clear these energy drinks aren't a substitute for drink and anybody considering taking one of those products first consult a physician. you might have an underlying health concern. >> different people react to things differently. allergens don't affect all people the same way, and energy drinks similarly don't react to people's bodies equally. >> bob barnard reporting for us. >>> u